The vidame was originally, like the avoue (advocatus), an official chosen by the bishop of the diocese, with the consent of the count.
But the causes that changed the character of the advocatus operated also in the case of the vidame.
With the crystallization of the feudal system in the 12th century the office of vidame, like that of avoue, had become an hereditary fief.
Thus the vidame de Picquigny was the representative of the bishop of Amiens, the vidame de Gerberoy of the bishop of Beauvais.
Saisset was on the point of escaping to Rome when the vidame of Amiens surprised him by night in his episcopal palace.